1. Technical Field
The present invention relates to a method of manufacturing a part of a microelectromechanical system (MEMS) that includes bonded body in which a first base member and a second base member are partially bonded together through a bonding film and a bonded body manufactured using such a method.
2. Related Art
Conventionally, when two members (base members) are bonded together to obtain a bonded body, a method, in which the two members are bonded together through an adhesive layer formed of an adhesive such as an epoxy-based adhesive or an urethane-based adhesive, has been often used.
In general, an adhesive exhibits reliably high adhesiveness regardless of constituent materials of the members to be bonded. Therefore, members formed of various materials can be bonded together in various combinations.
For example, a liquid droplet ejection head (an ink-jet type recording head) included in an ink-jet printer is assembled by bonding, using an adhesive, several members formed of different kinds of materials such as a resin-based material, a metal-based material, and a silicon-based material together.
When the members are to be bonded together using the adhesive to obtain an assembled body composed from the members, a liquid or paste adhesive is applied to surfaces of the members, and then the members are attached to each other via the applied adhesive on the surfaces thereof and firmly fixed together by hardening (setting) the adhesive with an action of heat or light.
However, in the case where the members are bonded together using the adhesive, there are problems in that (i) bonding strength between the members is low, (ii) dimensional accuracy of the obtained assembled body is low (for example, the adhesive is squeezed out from the assembled body), (iii) it takes a relatively long time until the adhesive is hardened, and (iv) the adhesive has low ink resistance (high resolvability against an organic solvent).
Further, it is often necessary to treat the surfaces of the members to be bonded using a primer in order to improve the bonding strength between the members. Therefore, additional cost and labor hour are required for performing the primer treatment, which causes an increase in cost and complexity of the process for bonding the members.
On the other hand, as a method of bonding members without using the adhesive, there is known a solid bonding method. The solid bonding method is a method of directly bonding members without an intervention of an intermediate layer composed of an adhesive or the like (see, for example, JP-A-5-82404).
Since such a solid bonding method does not need to use the intermediate layer composed of the adhesive or the like for bonding the members, it is possible to obtain a bonded body of the members having high dimensional accuracy.
However, the solid bonding method has the following problems: (A) constituent materials to be bonded are limited to specific kinds, (B) a heat treatment using a high temperature (e.g., about 700 to 800° C.) must be carried out in a bonding process, (C) an ambient atmosphere in the bonding process is limited to a reduced atmosphere, (D) since it is difficult to obtain a bonded body in which two members are partially bonded together, large stress due to a difference between thermal expansion coefficients of the two members is likely to be generated in a bonding interface therebetween, resulting in separation of the members of the bonded body.
In view of such problems, there is a demand for a method which is capable of partially and firmly bonding members with high dimensional accuracy and efficiently bonding them together at a low temperature regardless of constituent materials of the members to be bonded.